1. Field of the Invention
The present invention relates to the field of fastening devices, and particularly, to a fastening device which is utilized in the form of a stud and receptacle.
2. Description of the Related Art
Many types of fastening devices have been used for releasably securing one or more panels to a frame, or one panel to another. It is known to provide studs, such as, for example, quarter-turn fasteners which are received in a variety of associated receptacles. Some studs are provided to spread the receptacle to provide positive engagement against withdrawal of the stud and receptacle in order to retain a panel or other attaching member.
A need exists for a fastening member which can be readily installed to hold a panel onto a frame or other member, and which has the ability to succumb to predetermined force loads so that the fastener can destruct, thereby permitting the panel to become free.
It is particularly useful in the automotive industry to have members which can become disassociated and/or detached from other members upon the impact such as a crash. For example, where snow and ice are prevalent, often, noise panels, which are installed underneath the carriage of an automobile, can become jarred by their contact with snow and/or ice or other objects. Instead of having the panel damaged or ripped, it is more desirable that the panel fastening members, such as a fastening stud, release and then permit the panel to become detached as a whole rather than as a fragmented collection of pieces. This promotes reuse of the panel and minimizes further damage to the surfaces involved. Furthermore, it is useful if the receptacle can be reused, if it itself is not damaged.
Furthermore, often noise panels are attached to other members, such as the bumper of a car, headlamps, fog lamps, grilles and other vehicle components, which are costly to replace, in the event that they would come off with the panel. Therefore, it is preferable to provide a means for fastening such a panel to a vehicle which will release itself from the vehicle, and the other vehicle components to which it is attached, while minimizing damage to further parts of the vehicle.
The present invention provides a fastening device comprising a receptacle and a stud fastening member for use in connection therewith. The fastening device of the present invention is designed for high intermittent loads and has predetermined forced specifications for maintaining a static load and has a threshold peak working load. For example, the fastening device may operate under a steady state load of 50 Newtons (N) and may have a peak working load of 800 N. The fastening device preferably includes a receptacle and a stud. After exceeding the peak working load, the stud will shear, and therefore permit release of the panel or member which it is attaching.
Preferably, the stud is made of a plastic and is composed to provide shearing at the desired operative peak or threshold load force. The plastic preferably, is a corrosion-resistant material which improves the durability of the fastening members.
A clip-on type receptacle is preferably provided for use with the fastening stud member. Preferably, a wave-shaped configuration provides an interaction zone with a maximum load bearing area between the stud and receptacle surfaces. Preferably, the stud is configured with enlarged radial end portions to facilitate distribution of force loads so that stress concentrations at the lugs of the stud can be reduced. The receptacle and stud, together, cooperate to provide a predetermined breakpoint for predictable shear failure at predetermined operating/stress loads.
The stud preferably has an enlarged end configuration with a wave shaped interaction zone. The receptacle is provided with a compatibly associated wave-shaped interaction zone to permit retention of the stud when the stud is turned, such as, a quarter-turn, to fasten the stud with the receptacle. Preferably, the receptacle is a clip-on type and can be clipped to the edge of a panel or frame.